Codeforces Round #182 (Div. 1) A:http://codeforces.com/contest/301/problem/A 题意:给你2*n-1个数,你每次可以选择n个连续的数,把这个n个数*-1,问你进行若干次操作,这2*n-1个数之和最大是多少. 题解:结论很简单:当n是奇数的时候,那么你一次操作可以增加或者减少一个负数,所以这时候所有的负数都能变成整数.当n是偶数的时候,那么你一次操作可以增加或者减少2个负数,如果负数的个数是偶数,那么所有的负数都可以变成整数…

A. Eugeny and Array \(r-l+1\)是奇数时,和显然无法为0. 奇数的情况需要判断-1和1的个数是否大于等于长度的一半. B. Eugeny and Play List 模拟. C. Yaroslav and Sequence 当负数个数和\(n\)同奇偶时,所有数都可以转化成整数.(随便拿n-1个数和其中一个负数操作,然后再拿另一个负数和这n-1个数再操作即可).同奇偶,可以转变负数个数. 当负数为偶数时,最后都会变成整数. 否则,最后剩下一个负数时,与整数的最小值对换,…

oracle创建序列化: CREATE SEQUENCE seq_itv_collection            INCREMENT BY 1  -- 每次加几个              START WITH 1399       -- 从1开始计数              NOMAXVALUE        -- 不设置最大值              NOCYCLE               -- 一直累加,不循环              CACHE 10; oracle修改序列…

功能:备份存储过程,视图,函数触发器,Sequence序列号等准备工作:--1.创建文件夹 :'E:/OracleBackUp/ProcBack';--文本存放的路径--2.执行:create or replace directory MyProcBakPath as 'E:/OracleBackUp/ProcBack';--3.赋权限:sqlplus /nologconn user/pswd as sysdbagrant select on DBA_OBJECTS to user;--4.创建…

环境:Oracle 11.2.0.4 DG 故障现象: 客户在备库告警日志中发现GAP sequence提示信息: Mon Nov 21 09:53:29 2016 Media Recovery Waiting for thread 1 sequence 12034 Fetching gap sequence in thread 1, gap sequence 12034-12078 Mon Nov 21 09:55:20 2016 FAL[client]: Failed to request…

The set [1,2,3,-,n] contains a total of n! unique permutations. By listing and labeling all of the permutations in order,We get the following sequence (ie, for n = 3): "123" "132" "213" "231" "312" "3…

Check whether the original sequence org can be uniquely reconstructed from the sequences in seqs. The org sequence is a permutation of the integers from 1 to n, with 1 ≤ n ≤ 104. Reconstruction means building a shortest common supersequence of the se…

Given a binary tree, find the length of the longest consecutive sequence path. The path refers to any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The longest consecutive path need to be from p…

Given an array of numbers, verify whether it is the correct preorder traversal sequence of a binary search tree. You may assume each number in the sequence is unique. Follow up: Could you do it using only constant space complexity? 这道题让给了我们一个一维数组,让我们…

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example, Given [100, 4, 200, 1, 3, 2], The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4. Your algorithm should run i…